Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Pentax K10D and Leica X1 side-by-side from the front, back and top in their relative dimensions. Pentax K10D has external dimensions of 142 x 101 x 70 mm (5.59 x 3.98 x 2.76″) and weighs 793 g (1.75 lb / 27.97 oz) (including batteries). Leica X1 has external dimensions of 124 x 60 x 32 mm (4.88 x 2.36 x 1.26″) and weighs 306 g (0.67 lb / 10.79 oz) (including batteries).
Below you can see the front view size comparison of Pentax K10D and Leica X1. Leica X1 is clearly the smaller of the two cameras. Its body is 18mm narrower, 41mm shorter and 38mm thinner than Pentax K10D. As you can tell, actually this is not a fair size comparison since Leica X1 has a built-in lens but Pentax K10D doesn't. Once you put a lens on K10D, its thickness will increase significantly.
Now lets look at the top view comparison of Pentax K10D and Leica X1.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Leica X1 is significantly lighter (487g ) than the Pentax K10D which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on K10D, the total kit will weigh much higher.
With its weather sealed body, we believe that K10D has a big advantage over X1 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Leica X1's 2.70" LCD screen is slightly larger than Pentax K10D's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.